Does your thermostat ever go past the halfway point? I had problems also driving my car in hot weather where the temperature of my engine would rise, that's normal for cars in hot weather. Since we have turbo's, oure engines get warm quick at idles. But once you are moving around 40mph+ it starts to cool off. Just make sure to keep your engine oil checked and cleaned. Clean oil lubes your engine better, making for less friction and strain on the engine. During the summer, I change my oil ever 2k miles.